In a registered letter from February 1942, the Inspector of the Concentration Camps ordered the commandants of all large main camps – including Dachau, Sachsenhausen, Ravensbrück and Natzweiler – to make more prisoners available for labor assignments. To this end, they were supposed to reduce the number of people working in the camps; a maximum of 10 percent of all prisoners were to be assigned to work within a camp.